The present invention relates to an active head restraint for an automotive seat, with an integrated gas bag module of such type, that in a crash, especially a rear-end impact of the vehicle, the distance between the head of the person in question and a supporting surface of the head restraint is actively diminished.
Such a head restraint is known from the publication DE 29808982U1. In this case, the gas bag itself emerges out of the head restraint, passing through a module bolster, to reduce the distance to the head of the vehicle occupant. A quite unpredictable and therefore possibly inadequate support for the head could result thereby, above all indeed, if the person should not happen to be seated precisely aligned relative to the head restraint in a xe2x80x9cnormal seating position,xe2x80x9d a seating also known as xe2x80x9cOut Of Positionxe2x80x9d (OOP).
The publication DE 29710511U1 describes a head restraint with a so-called expansion device, which increases the head restraint""s effective supporting surface in the restraining event, so doing in vertical and/or horizontal direction. At the same time, the entire head restraint is additionally readjusted upwards relative to the seat back, if the head restraint is arranged so close to the back rest that the back rest would prevent complete enlargement of the supporting surface in the vertical direction. The enlargement of the supporting surface can be achieved by inflating a gas bag or by a purely mechanical device, for example by swinging levers or by individual cushion units that move apart. In addition, the entire head restraint can also be moved closer to the occupant""s head in a restraining event.
It is the objective of the present invention to create a head restraint that guaranties increased safety by means of optimized head support with structurally simple and economic means, wherein in particular a simple and rapid reestablishment is also to be possible after a restraining event.
This is achieved according to invention by a head restraint with the characteristics of claim 1. Advantageous further developments and design characteristics are contained in the dependent claims.
According to invention, the head restraint consequently consists of a base component connected to the seat or its back rest, and an additional separate headrest support component, wherein this support component is detachably connected with the base component and a gas bag module is arranged integrated between the base component and support component in such a manner that, in a restraining event detected by sensors, the headrest support component is released from the base component by inflating a gas bag and moved to reduce the distance to the head of a person seated on the seat. Since the headrest support component itself consists of a relatively solid, dimensionally stable material, both the size and shape of the surface of the headrest fastened on the support component remain unchanged while the gas bag inflates, the surface working as a supporting surface. This guarantees a defined head support.
In a preferred embodiment, the detachable connection between the base component and the headrest support component is implemented by fasteners of such a type, that release of the support component from the base component basically only occurs by triggering the gas bag module, and release through manual manipulation is largely excluded. Such manual manipulations can involve resetting the head restraint for the purpose of changing the height and/or inclination. The fasteners ensure that the headrest support component is well mounted upon the base component against relative movements in the direction of the vehicle""s transverse axis (Y) and in the direction of the vehicle""s vertical axis (Z).
In a preferred embodiment of the invention, it is additionally provided that, in the restraining event, the gas bag enlarges an efficient impact surface in the vertical and/or horizontal direction. For this, the gas bag preferably includes a border region which emerges outwards from the head restraint, i.e. in the Y and Z directions, to enlarge the impact surface in the restraining event, and then completely encloses the headrest frame-like. In most cases, this will then also ensure adequately good head support if the person is situated in a so-called out of position situation.
The gas bag module is lodged in a receptacle within the base component, wherein the receptacle is practically covered lid-like and locked by the headrest support component. The gas bag module can therefore be installed and disassembled in a simple manner, and also be exchanged. The module is detachably fastened by suitable fasteners and connected with a sensor trigger by electrical connecting means. In the case in which, for example, the gas bag module is to be inspected or exchanged without the gas bag first having released the headrest support component from the base component in a restraining event, the support component can be released from the base component on a compulsory basis by appropriate means and the gas bag module""s receptacle can thereby be opened, for example with the aid of a tool and/or manually by applying a sufficiently high force that is higher than normal manipulative forces used to adjust the head restraint.